U.S. Pat. No. 5,463,455 describes an electrostatographic printer in which, at selected times, a lubrication stripe or “lube stripe” is placed on a rotating photoreceptor, using the same hardware as used to place images to be printed, such as imaging and development units. The lubrication stripe is a small strip of toner that contacts and thereby lubricates a cleaning blade.
The cleaning system in the '455 patent relies on an unbiased “disturber brush” and a cleaning blade that removes essentially all of the excess toner desired to be cleaned from a photoreceptor surface. However, high-speed and color printers often use an “electrostatic brush cleaner” in their cleaning systems. In an electrostatic brush cleaner, at least one rotating brush is strongly biased to a polarity suitable for electrostatically attracting the excess toner to be cleaned. Downstream of the brush is what is called a “spots blade,” which differs from a straightforward cleaning blade in that it is largely optimized to remove toner spots that are not typically removed by the brush. U.S. Pat. No. 5,339,149 discloses a basic design of an electrostatic brush cleaner with a spots blade. U.S. Pat. No. 6,925,282 teaches the same basic design, but further discusses the technological problem with keeping a spots blade properly clean.